gjdonatiello
Andromeda and its stellar halo
The monstrous beauty of Andromeda and its stellar halo
Credit: Giuseppe Donatiello
(J2000) RA: 00h 42m 44.3s Dec: +41° 16′ 9″ (core)
The Andromeda Galaxy, or Messier 31 (M31) and NGC 224, is a spiral galaxy approximately at 780 kiloparsecs (2.5 million light-years). It is the largest menber of the Local Group of galaxies, which also contains the Milky Way, the Triangulum Galaxy, and other smaller galaxies.
This image offers a good overview of the main structures on the disc and the outer stellar halo of Andromeda (M31).
The disc appears quite regular and there is an abundant presence of young stars, gases and dusts. The bulge is dominated by an older population. The external halo presents various irregularities and thickenings that we can consider as vestiges of dwarf galaxies incorporated progressively by the greater galaxy, as foreseen by the growth models.
M31 is thought to have assimilated a hundred small galaxies or globular clusters. This process is still ongoing.
Stack of images collected over the last 5 years, primarily with the array of telephoto lenses made up of two 300mm f/4.5, one 110/250mm (f2.2) and two 200mm. That's about 250 hours of total exposure from an SQM 21.8 mountain sky using DSLRs at 3200/6400 ISO.
Full resolution image (100MB) unlabeled: flic.kr/p/2nV2hnf
For details on the nomenclature, please see here:
The information and annotations in the image are of scientific utility because they identify the subject and place it in a specific moment. They also indicate the subject of interest. The absence of such information makes the images useless.
Andromeda and its stellar halo
The monstrous beauty of Andromeda and its stellar halo
Credit: Giuseppe Donatiello
(J2000) RA: 00h 42m 44.3s Dec: +41° 16′ 9″ (core)
The Andromeda Galaxy, or Messier 31 (M31) and NGC 224, is a spiral galaxy approximately at 780 kiloparsecs (2.5 million light-years). It is the largest menber of the Local Group of galaxies, which also contains the Milky Way, the Triangulum Galaxy, and other smaller galaxies.
This image offers a good overview of the main structures on the disc and the outer stellar halo of Andromeda (M31).
The disc appears quite regular and there is an abundant presence of young stars, gases and dusts. The bulge is dominated by an older population. The external halo presents various irregularities and thickenings that we can consider as vestiges of dwarf galaxies incorporated progressively by the greater galaxy, as foreseen by the growth models.
M31 is thought to have assimilated a hundred small galaxies or globular clusters. This process is still ongoing.
Stack of images collected over the last 5 years, primarily with the array of telephoto lenses made up of two 300mm f/4.5, one 110/250mm (f2.2) and two 200mm. That's about 250 hours of total exposure from an SQM 21.8 mountain sky using DSLRs at 3200/6400 ISO.
Full resolution image (100MB) unlabeled: flic.kr/p/2nV2hnf
For details on the nomenclature, please see here:
The information and annotations in the image are of scientific utility because they identify the subject and place it in a specific moment. They also indicate the subject of interest. The absence of such information makes the images useless.